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Lack of cytosolic glutamine synthetase1;2 in vascular tissues of axillary buds causes severe reduction in their outgrowth and disorder of metabolic balance in rice seedlings
Author(s) -
Ohashi Miwa,
Ishiyama Keiki,
Kusano Miyako,
Fukushima Atsushi,
Kojima Soichi,
Hanada Atsushi,
Kanno Keiichi,
Hayakawa Toshihiko,
Seto Yoshiya,
Kyozuka Junko,
Yamaguchi Shinjiro,
Yamaya Tomoyuki
Publication year - 2015
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12731
Subject(s) - strigolactone , axillary bud , vascular bundle , lignin , biology , glutamine , vascular tissue , shoot , phloem , mutant , biochemistry , tiller (botany) , cytosol , botany , microbiology and biotechnology , gene , enzyme , tissue culture , in vitro , arabidopsis , amino acid
Summary The development and elongation of active tillers in rice was severely reduced by a lack of cytosolic glutamine synthetase1;2 ( GS 1;2), and, to a lesser extent, lack of NADH ‐glutamate synthase1 in knockout mutants. In situ hybridization using the basal part of wild‐type seedlings clearly showed that expression of O s GS 1;2 was detected in the phloem companion cells of the nodal vascular anastomoses and large vascular bundles of axillary buds. Accumulation of lignin, visualized using phloroglucin HC l, was also observed in these tissues. The lack of GS 1;2 resulted in reduced accumulation of lignin. Re‐introduction into the mutants of O s GS 1;2 c DNA under the control of its own promoter successfully restored the outgrowth of tillers and lignin deposition to wild‐type levels. Transcriptomic analysis using a 5 mm basal region of rice shoots showed that the GS 1;2 mutants accumulated reduced amounts of m RNA s for carbon and nitrogen metabolism, including C 1 unit transfer in lignin synthesis. Although a high content of strigolactone in rice roots is known to reduce active tiller number, the reduction of outgrowth of axillary buds observed in the GS 1;2 mutants was independent of the level of strigolactone. Thus metabolic disorder caused by the lack of GS 1;2 resulted in a severe reduction in the outgrowth of axillary buds and lignin deposition.